Process for treating glass fabric



Feb. 4, 1969 B. M. KEASLER I PROCESS FOR TREATING GLASS FABRIC Filed Jan. 25, 1965 R 325 6 3222 ME T 3:25. QEQE qhwwu m 0E mm 253. 3&2 3G5 Wm m A M T T E N N a 3:25. 3222 323.6 zu 2 2mm: 2,55. 2mm: 4 0E2. m 0; 8%.; 325 8 35:6 3:; 3553 mo 3:22.. 32330 3. amzwtom zm oa may fig. g1 Szutom United StatesPatentOflice Claims The present invention is concerned with glass fabric and, more particularly, relates to the preparation of glass fabric having lofty surface appearance.

Considerable effort has been directed towards producing woven glass fabric which has an appealing surface loft or textured appearance. Thus, for example, glass yarns have been textured in conventional fashion (such as by the well known Taslan process) and these yarns have been woven into a variety of fabric constructions to give a wide range of styling and appearance. It is possible by this yarn texturizing technique to obtain some improvement in loft and surface appearance. However, there is considerable room for further improvement in the product, particularly with respect to the amount of loft obtained. Additionally, the process is costly. I

The principal object of the present invention is to provide a novel method for providing glass fabric'having a lofty surface. Another object of the invention is to provide a method of the type indicated which gives better loft and surface appearance than the procedures previously known and used. Still another object is the provision of a .method which is economical and commercially useful for providing a highly desirable lofty appearance on woven glass' fabric. Other objects will also be hereinafter apparent.

Broadly defined, the process of the invention involves napping a glass fabric while it is in the unfinished state, i.e. before any finishing operation has been applied. The fabric may be napped according to the invention while it is in the untreated greige or loom state or the fabric may be prescoured and/or heat cleaned. However, best results are obtained if a conventional softener is to the fabric prior to the napping operation.

Any conventional type of napping means may be used in the practice of the present invention, e.g. the apparatus illustrated in US. Patents 2,469,245; 2,684,519 and 2,700,- 202. The goods, erg. fabric in the untreated greige or loom state or fabric which has been subjected only to prescouring, heat cleaning and/or application of a softening material, may be passed through the napping means one or more times to give the desired result. The number of passes employed will vary, depending on other operating factors, e.g. the construction of the fabric and the napping means but usually optimum results are obtained using from one to four passes through the napping means.

Any type of woven glass fabric, decorative or industrial type, may be processed according to the present invention to obtain improved loft and otherwise desirable effects. This includes fabric made up with plain glass yarn (i.e. nontextured, conventional glass fibers) and/or with textured forms of glass yarn. While textured yarns will give a lofty product without napping of the greige goods, the results are substantially enhanced using the present process, particularly if the goods are treated with a softening material (usually by padding and drying) before napping. The improved loft obtained with the present invention using industrial type fabrics makes it possible to greatly increase the interlaminar bond strength of laminated glass fabrics.

The glass yarns used herein may be of the continuous filament or spun ya-rn type and will usually have a size applied 3,425,109 Patented Feb. 4, 1969 or weight in the range of 180,000 yds./lb. to one yd./lb. Twist will generally be from 'zero to ten turns per inch. Plied or single ends may be used. Other useful characteristics in the yarns preferably employed herein include softness of the individual yarns and diameter of individual filaments.

Conventional types of decorative and industrial weaves and fabric constructions may be used herein (e.g. 2 x 2 or 1 x 1 plain weaves). However, best results are obtained using fabric constructions which have filling float yarns on the surface. Filling float yarns are well known in the art and may be defined as yarns which extend over two or more warp ends in a woven fabric. For optimum results, there should be from 8 to float yarns per inch of picks on the surface of the fabric although more or less than this number may be used. The effect produced is dependent upon the fact that while glass fibers are exceptionally strong in the longitudinal direction, they are weak in the lateral direction or at right angles to the axis of the fiber. The napping means applies its energy to the fabric in the warp direction, or in a direction perpendicular to the direction of the lay of the filling yarns; therefore, the length of the filling float yarns, and the arrangement of these yarns into a suitable woven pattern is important, as this influences the degree to which the filaments of the filling yarns are ruptured and the degree of loft obtained. Yarns laying in the warp direction are not broken or napped by the napping means due to the strength of the filaments in the longitudinal direction and the application of the energy of the napping means in a direction parallel to the lay of the warp yarns. Usually, the fabric as woven will include up to 10.0% by weight of a conventional size, e.g. starch, dextrin, oils, polyvinyl alcohol or the like (see US. Patents 2,688,007; 2,938,812 and 2,965,515). In the case of a fabric with float yarns, the bulk of the size (i.e. 50 or more) will be on the non-float yarns making up the fabric. This appears to be an advantageous feature for present purposes.

Scouring, heat cleaning and/or softening may precede the napping operation according to the invention and, as noted, best results are obtained if a softening material is applied before napping. However, if desired, the scouring, heat cleaning and/or softening application may follow the napping operation. In any case, these treatments are not considered finishing operation in the art. The finishing operations as known in the .art involve the final processing steps, such asdyeing, printing or otherwise coloring of the fabric (as shown, for example, in US. Patents 2,971,864 and 2,754,224); resin treatments; the application of chrome complexes (US. Patents 2,356,161 and 2,273,040); treatments with colloidal silica and organosilicon compounds to facilitate coloring as described in U.S. Patent 2,754,224; carmelizing and the like. As noted earlier, these finishing operations must come after the napping operation if the results of the invention are to be realized.

Where the fabric is pre-scoured or heat cleaned or a softener is applied, before or after napping, conventional operations may be used. For example, the fabric may be heat cleaned (or colonized) as described in US. Patents 2,970,934 and 3,012,845. The softener application may be accomplished by padding in an aqueous solution or dispersion of one or more conventional softeners (e.g. Sapamine W. L., Avitex or protamine) followed by drying at 200 to 400 F. Scouring may be carried out using hot or cold water with or without detergent as the scouring medium followed by drying.

Typical fabric constructions suitable for the treatment by the'flow sheets constituting FIGURES I -3. In FIG- described herein include. .thefollowing: -.-.-.-..-W.-.- URE- 1, the.'woven fabric in the greigestate is.,shown being FABRIC 1 softened or scoured followed by napping, heat cleaning 58 ends x 60 picks ECB glass yarn-150 1/0 warp and fill v 6 float yarns per inch of picks FABRIC 2 (CASEMENT) 56 ends x 54 picks ECDE glass yarn-150 1/0 warp and fill float yarns per inch of picks FABRIC 3 (CASEMENT) 56 ends x 54 picks ECDE glass yarn-150 1/0 'warp and fill 5 /2 float yarns per inch of picks FABRIC 4 56 ends x 54 picks ECDE glass yarn-150 l/O warp and fill 5 /2 float yarns per inch of picks FABRIC 5 42 ends x 32 picks ECG 150-1/2 warp and fill 16 float yarns per inch of picks The following examples are illustrative of preferred operations according to the invention:

Example 1 Fabric 1 above was woven on a standard type loom (e.g. single shuttle or box loom). The greige fabric taken from the loom was fed directly from the loom through a conventional napper, i.e. without any previous treatment such as scouring, heat cleaning, softening or finishing. One pass through the napper was used. The napping means comprised a revolving roll carrying appropriate teasels, card clothing or wire. The fabric was drawn over the revolving roll in a tightly stretched condition and at a rate of 52.5 feet per minute.

After napping, the fabric was coronized by heating at 1250 F. for about -15 seconds and then finished by padding with pigment dispersed in acrylic resin, drying at 380 F. and curing at 400 F., followed by padding with chrome complex (e.g. Quilon) and drying.

The resulting product demonstrated an extremely desirable lofty surface with excellent hand and appearance, far superior to the characteristics of fabric processed in the same way but omitting the napping operation or napping after finishing.

Example 2 The procedure of Example 1 was repeated on Fabric No. 2 except that the greige fabric was coronized before napping rather than after napping to obtain an improvement in left over untreated fabric.

Example 3 The procedure of Example 1 was repeated on Fabric No. 3 except that the greige goods were softened by padding with an aqueous dispersion of softener (e.g. Sapamine W.L. or equivalent) followed by drying at 350 F., before napping. The resulting product demonstrated a slight improvement of loft over that demonstrated by the product of Example 1.

Example 4 The procedure of Example 1 was repeated on Fabrics Nos. 4 and 5 except that the fabrics utilized were ones wherein the yarns had previously been textured following the so-called Taslan method. The finished products had excellent lofty surfaces and were superior in all respects to corresponding products using textured yarn.

Various embodiments of the invention are illustrated and finishing. In FIGURE 2, the greige fabric is heat cleaned before napping and finishing while in FIGURE 3, the greige goods are napped directly, cleaned and finished.

The term loft is used herein in the conventional'art sense to mean bulking of the yarn and breaking of the continuous filaments to give cover to the fabric and to increase thickness and fullness of hand and aesthetic value of fabric. v 4 v It will be recognized that various modifications may be made in the invention described herein. Hence, the scope of the invention is set out in the following claims wherein I claim:

1. In the process for preparing a lofty surface on a woven glass fabric wherein the woven fabric is subjected to a finishing and napping operation, said finishing operation being at least one final process step comprising dyeing, printing, coloring, resin treatment, chrome complex treatment, colloidal silica and organosilicon treat ments and caramelizing, the improvement comprising napping the woven glass fabric in an unfinished state and thereafter finishing the napped fabric, whereby the resulting loft on the glass fabric surface is greater than that obtainable by finishing the glass fabric and subsequently napping the glass fabric.

2. The process of claim 1 wherein the fabric is softened before napping and finished after napping.

3. The process of claim 1 wherein the fabric is subjected to at least one treatment selected from the group consisting of heat cleaning, scouring and softening, thereafter napped and then finished by dyeing and resin treatment.

4. The process of claim 1 wherein the fabric is napped in the greige state and thereafter cleaned and finished.

5. The process of claim 1 wherein greige fabric is cleaned before napping and the cleaned fabric is napped before finishing.

6. The process of claim 1 wherein the said napping is carried out in more than one step.

7. 'T he process of claim 1 wherein the glass fabric is in a dry state during the said napping operation.

8. In the process for preparing a lofty surface on a woven glass fabric wherein the woven fabric is subjected to a finishing and napping operation, said finishing operation being at least one final process step comprising dyeing, printing, coloring resin treatment, chrome complex treatment, colloidal silica and organosilicon treatments and caramelizing, the improvement comprising napping the woven glass fabric in an unfinished state and thereafter finishing the napped fabric, whereby the resulting loft on the glass fabric surface is greater than that obtainable by finishing the glass fabric and subsequently napping the glass fabric, said fabric having from 8 to float yarns per inch of picks.

References Cited UNITED STATES PATENTS 2,208,090 7/ 1940 Whittier 139-420 XR 2,303,534 12/1942 Foster 139-420 XR 2,991,536 7/1961 Moler 28-72.2 XR 2,993,261 7/1961 Sunbury 28-76 3,117,052 1/ 1964 Horton 28-74 XR 3,175,273 3/1965 Falls et al. 28-75 2,194,860 3/1940 Martin 161-64 ROBERT R. MACKEY, Primary Examiner.

US. Cl. X.R. 

1. IN THE PROCESS FOR PREPARING A LOFTY SURFACE ON A WOVEN GLASS FABRIC WHEREIN THE WOVEN FABRIC IS SUBJECTED TO A FINISHING AND NAPPING OPERATION, SAID FINISHING OPERATION BEING AT LEAST ONE FINAL PROCESS STEP COMPRISING DYEING, PRINTING, COLORING, RESIN TREATMENT, CHROME COMPLEX TREATMENT, COLLOIDAL SILICA AND ORGANOSILICON TREATMENTS AND CARAMELIZING, THE IMPROVEMENT COMPRISING 